Safety device for electric elevators



(No Model.) 2 Sheets-Sheet 1. N. P. OTIS & R. 0. SMITH.

SAFETY DEVIOE FOR ELECTRIC ELEVATORS.

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WITNESSES X (No Model.) 2 Sheetsf-Shet 2. N. P. OTIS & R. 0. SMITH.

SAFETY DEVICE FOR ELECTRIC ELEVATORS.

No. 458,977. Patente Sept. 1 1891.

WITNESSES JZEJVTORS 20" M .w .26 3 M M Attorney;

UNITED STATES NORTON P. OTIS AND RUDOLPH 0.

SMITH, OF YONKERS, NEW YORK,

ASSIGNORS, BY MESNE ASSIGNMENTS, TO HE NATIONAL COMPANY,

OF ILLINOIS.

SAFETY DEVICE FOR ELECTRIC ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 458,977, dated September 1, 1891.

Application filed December 31-, 1890.

To all whom it may concern:

Be it known that we, NORTON P. OTIS and RUDOLPH 0. SMITH, citizens of the United States, residing at Yonkers, in the State of New York, have invented certain new and useful Improvements in Safety-Guards for Elevators, of which the following is a specification.

The object of our invention is to provide means whereby the operator in the cage of an elevator may be notified of any change of the operation of the engine and to provide safeguards whereby to prevent a series electromotor from using an unnecessary amount of current beyond that required for the work which it is required to do; and to these ends we provide the cage with an indicator, with means for operating it upon an undue change in the speed of the engine, and in the case of an electrical engine we provide means whereby the operator in the cage can control the operating extent of the field -magnet, and whereby friction is automatically applied to prevent any undue increase of motion of the engine.

In the accompanying drawings, Figure 1 is an elevation showing a passenger-elevator and engineembodying our improvements;

, Fig. 2, an enlarged side elevation of the engine; Fig. 3, a transverse sectional view on the line 3 3, Fig. 2, showing the car; Fig. 4, a diagrammatic illustration of the motor-controlling switch and circuits; Fig. 5, a motor showing a modified form of indicator.

The motor A may be of any of the wellknown types, with an armature 1 upon a shaft 2 and revolving between the poles of the fieldmagnets N S, the multiple coils of which connect with one section of the main line and terminals between the central terminal 5 and the side terminal 7 or 8, the two arms being connected to swing together by a non con- Serial No. 376,382. (No model.)

ducting 0r insulating coupler-bar 12. These arms are connected as hereinafter described and illustrated, and with any suitable means for shifting them.

The arm 9 is electrically connected with one of the armature-brushes and the arm 10 with the other brush of the armature, and the terminals of the field-magnet coils are properly looped together-for instance, as in Fig. 4=to secure a correct action in diminishing v the motive force of the motor and in revers- 6o ing the current and direction of rotation of the'armature. Thus when the parts are in the position shown in full lines, Fig. 4, the line is open. No current can pass to the motor, andthe latter is at rest.

When the parts are shifted to the position shown in dotted lines, Fig. 4, the arm 10 is upon 'theterminal 5 and the arm 9 on the terminal 7 to complete the circuit in such manner as to secure the maximum strength of the field and the highest eleetro-motive force of which= the machine is capable. If the switch is thrown to the right instead of to the left to bring the arm 9 onto the terminal- 5, the same result will be attained; but the 7 5' armatu r'e will be reversed in its direction of motion. If the power developed is greater than is required, the effective operation of the machine is reduced by shifting the arms of the switch S onto one or the other of the terminals 3 3 01-4.- e, cutting out a portion of the field-coils.

In order to adapt the use of the motor and its regulating-switch device for service in an elevator apparatus, we combine with the switch, constructed as described or in any other manner to secure the same result, appliances whereby the said switch may be shifted to one side or the other and set at any intermediate point at either side by the act 0 of the operator or attendant in the cage. One construction of appliances is illustrated in the drawings and will now be described. The arm 9 is secured to a short pivotal shaft 13, rocking in suitable bearings and carrying a 5 pinion 14, which gears with the teethiof the sector-lever 15, pivoted between its ends and slotted to receive the pin upon the sliding shifter-bar 16. A second sector-lever 17 is also slotted to receive a pin from the shifterbar and gears with a pinion 18 upon a sleeve attached to a pulley 19, round which passesa hand-rope 20, extending through the car X of the elevator. It will be seen that by means of the appliances described the attendant in the elevator-cage by moving the hand-rope 2O upward or downward and to any desired extent may shift the switch to. one side or the other or set it at any intermediate point, and thereby he can control the working power of the engine, proportioning it to the load to be lifted or lowered.

In order to avoid the necessity of constant observation of the running of the engine and of mistakes from the ignorance or carelessness of the operator, we combine with the cage an indicator I and with the engine a governor C, which controls the current or other force operating the indicator. The indicator may be of any suitable character, as an alarm operated by an electric current or otherwise, a

, visual signal in the form of an electric lamp, as shown in Fig. 3, or a pointer operated by a weight and piston propelled by variations in a fluid column, as shown in Fig. 5. The governor may be constructed in any suitable manner so as to vary the current or the fluid column or other signal-actuating means, an ordinary ball-governor be? n g shown driven from the engine and shifting a circuit-closer 0, so as to make contact with the two terminals a and b when the speed of the engine becomes excessive, and to thereby complete a circuit including a battery Z and a signal in the car. By means of a governor and signal device the operator is warned upon any undue increase in the speed of the motor, so that he can thereupon shift the switch to revduce the power of the engine; but in order to prevent accidents from any negligence of the indications of the signal we combine with the engine a brake device J, whereby sulficient mechanical resistance is applied to the moving part of the engine by the action of the governor to prevent excessive speed if the operator fails to shift the switch and cut out the field-coils. One construction for effecting this result is shown as consisting of a brake-lever 28, carrying a brake-shoe 21, which is brought against a brake-wheel 22 upon the shaft 2 by the action of the governor 0 when the speed of the engine such as to throw out the governor-balls beyond their normal limit. As shown, the circuitcloser c is carried by the brake-lever 28 and is so arranged as to close the circuit including the indicator I before the brake is applied, so that the operator in the cage is warned before the speed of the en gine reaches its maximum limit.

It will be evident that an electric brake or other form of brake may be substituted for that shown, and that other forms of speed governors maybe employed.

In order to rapidly arrest the momentum of the machine when the main circuit is broken to stop the machine, we make use of a second brake device K, consisting of a weighted lever 23, carrying a shoe 24, adapted to be brought against the brake-wheel 22, and the lever K is provided with a roller or other bearing 25, resting upon the shifter-bar 16, which is notched, as shown in Fig. 2, so as to allow the lever 23 to descend and apply the brake-shoe to the friction-wheel as the switch is brought to its central position.

When the shifter-bar is moved to either side, the inclines orinclined sides of the notch lift the brake-lever and remove the shoe from the wheel.

It will be evident that some of the features described may bensed separately with other kinds of engines than that shown and described.

lVithout limiting ourselves to the precise construction and arrangement of parts shown. we claim 1. The combination, in an elevator, of a traveling cage or platform, a stationary series elect-romotor having the various field-magnet coils connected to the separate terminals, terminals for the main circuit, a switch arranged to break or shift the circuits to arrest, reverse, ahd vary the power of the engine, and appliances between the switch and the cage whereby the operator can shift the switch to arrest, reverse, and vary the speed of the engineand cage, substantiallyas set forth.

2. The combination, with the cage and a series electromotor having sectional field-magnet coils, a series of terminals connected with the sections of said field-magnet coils, and terminals arranged upon opposite sides of said series of terminals, of a switch provided with, two arms connected to move together over said terminals, and appliances between the switch and the cage for operating the switch from the cage, substantially as described.

3. The combination, with an elevator and electromotor for operating the same, of a governor or speed device operated by the motor and an indicator in the cage controlled by the governor to indicate to the operator any undue change in the speed of the engine, substantially as set forth.

at. The combination, with the cage, operating-engine and controlling devices therefor, and means for operating the same from within the cage, of aspeed device or governor driven from the engine, and an indicator within the cage and means for operating the same from the governor, substantially as and for the purpose set forth.

5. The combination of an elevator-cage, opcrating-engine, speed device operated therefrom, an electric circuit including an indicator in the cage, and circuit-closer connected to be operated by the speed device, substantially as set forth.

' (5. The combination, with the cage of an elevator and with the motor therefor, of a speed device driven from the motor, an indicater controlled thereby, and a friction-brake connected with the speed device to apply a frictional resistance to the motion of the parts when the speed of the motor becomes excessive, substantially as set forth.

7. The co1nbination,with an elevator-cage, electromotor, and switch, and connections whereby to stop, reverse, and vary the speed of the motor, of a friction-brake, an automatic speed device connected to be operated from the motor and to operate the brake, and a secondary brake device connected to be controlled from the cage substantially as set forth.

8. The combination, in an elevator, of the cage, an electromotor, a switch device arranged to regulate the extentof the field-coils required in the circuit and to break and reverse the circuits, connections between the switch device and the cage, and an automatic speed device operated by the motor for pre venting the excessive speed of the latter, substantially as described.

0. The combination, with the engine and shifter-bar, of a brake and inclines on the shifter-bar arranged to lift the brake when the bar is moved from its mid-position in either direction, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

NORTON P. oTIs. RUDOLPH 0. SMITH.

Witnesses:

HENRY L. BRANT, SAMUEL BURGER.

It is hereby certified that Letters Paitent No. 458,977, granted September 1, 1891, upon the application of Norton P Otis and Rudolph G. Smith, of Yonkers, N ewYork, for an improvement in Safety D'vices for Electric Elevatorsflfivere erroneously issued to the National Company, of Illinois, as sole owner of the said invention; that said Letters Patent should have been issued to said Norton 1;. Otis and the National 00mpanydoin tly, saidNaitionol Company being assignee of the interest of said Rudolph O. Smith only, as shown by the record of assignments in this office; and that said Letters Patent should be read with this oorrection'therein that the same may conform tothe record of the ease in the Patent Oifiee.

Signed, countersigned, and sealed this 15th day of September, A. D. 1891.

[SEAL] CYRUS BUSSEY,

Assistant Secretary of the Interior. Gountersigued:

'W.1.E. SmoNDs,

Commissioner of Patents,

It is hereby certified that Letters Patent No. 458,977, granted September 1, 1891, upon the application of Norton P, Otis and Rudolph O. Smith, of Yonkers, NewYork,

for an improvement in Safety Devices for Electrio Elevators,'were erroneously issued to the National Company, of Illinois, as sole owner of the said invention; that said Letters Patent should have been issued to said Norton 2. Otis and the National Company join tw, saidrNational- Company being assignee of the interest of said Rudolph O. Smith only, as shown by the record of assignments in this ofiice; and that said Letters Patent should be read with this correotiontherein that the same may conform tothe record of the casein the Patent Ofliee.

Signed, eountersigned, and sealed this 15th day-of September, A. D;189i.

CYRUS BUSSEY,

Assistant Secretary of the Interior. Countersigued:

W; E. SmoNDs,

Commissioner of Patents, 

